Boom stop for load handling machines



y 30, 1950 w. M. HUSTON 2,509,686

BOOM STOPFOR LOAD HANDLING MACHINES Filed July 5, 1945 4 Shee'ts-Sheet l(Deacon 3nneutor MMM 1 M Gtkornegs May 30, 1950 w. M. HUSTON 2,509,686

BOOM STOP FOR LOAD HANDLING MACHINES Filed July 5, 1945 4 Sheets-Sheet 2Smoentor May 30, 1950 w. M. HUSTON 2,509,686

BOOM STOP FOR LOAD HANDLING MACHINES Filed July 5, 1945 4 Sheets-Sheet 3()OOOOSOOOOC) Snnentor Gttornegs May 30, 1950 w. M. HUSTON BOOM STOP FORLOAD HANDLING MACHINES 4 Sheets-Sheet 4 INVENTOR. My 4. Mum

770R NE Y5 Filed July 5, 1945-.iltillIIouIllliilllllllllI!InIIllIlllililililllllllilillll PatentedMay 30, 1950 BOOM. STOP, FDR LOAD HANDLING I MACHINES William M. Huston;Lima; 0hio- ,ApplicationJulyfi, 1945, .Serial'No. 603,378

(Cl=.:212e--59) 3- Claims. '1

This invention relates to load handling-equip- ,ment, and particularlyto self-propelled load handling machines adapted to travel on crawlertreads. Ihe invention is especially concerned with a machine having anextended boom ,mounted for upward and downward swinging movement, forinstance, a crane.

With equipment of the character mentioned above, especially a. largesize machine having a long boom, the boomhas such mass that undercertain abnormal conditions (for instance, breakage of a sling whenhoisting a heavy load) the boom may tendto over-travel orswing'beyondthe upper limit ,of the normal operating range. It is a, primary objectof the invention to provide .mechanism for limiting upward swingingmovement .of the boom atthe upper end of the desiredrange of movement,which mechanism is of sturdy construction'an'dcapable of preventingover-travel of the boom under certain conditions, and tothereby avoidpossible damage to the machine and minimize tendency for the machine totilt rearwardly.

According to the structure provided by the invention, means are alsoprovided for cushioning the motion of the boom in the upward directionadjacentthe upper limit of. the movement.

More particularly, the invention contemplates the employment oftelescopically arranged members adapted to be extended and collapsedasthe boom swings, and acting in compression upon being collapsed tolimit upward swinging movement of the boom, the ends of the telescopicele- ,ments being associated, respectively, with the headofthe.gantryand with the boom at a point spaced appreciably from the footend. thereof, advantageously near tothe center oimassof. the boom.

.How the foregoing together with other objects and advantages areattained willappear .more fully from the following descriptiomreferringto the accompanying drawings in which.---

Figure 1 is a side outline view of a crane with the boom stop mechanismof the present invention applied thereto, withthe boom swung downwardlyto a substantially.horizontalposition, a portion thereof beingbrokenoutfortcompactness of the figure.

Figure 2 is a viewsim-ilar to Figure 1 but with theboom raised to anangle approximating 48 "from the horizontal, in which positionithextelescopic stop. members are partlyzcollapsed;

Figure. 3 is ,a viewsimilar to Figures 1 and 2 but illustrating theboomrat the upwardilimit of its pivotal. motion, with .the telescopicstop members completely collapsed.

Figure 4 isa plan. view,.on anenlargedsoale of the telescopic boomstops, with the telescoping parts thereof. positioned substantially in.accordance with the showing .inzFigureB.

2 Figure 5 is-a plan secti'onalview througnone of the telescopic' boomstop devices, with the partsthereof' completely telescoped, as in Figure3, FigureE being on astillfurther enlarged scale. 'Tliisvi'ew has partsbroken out for the sakeoi compactness;

Figure Gis: aview similar to Figure-'5 butxillus- 5 trati'ngthetelescoping parts extended.

Referring first to-Figuresl', 2 and 3," the rotating base *1 of thecrane there" shown is mounted for swingmotion on: the crawlertruckrstructure 8, 1 the truck being provided with crawlertreadsdiagrammatically i indicated at, 9, .by iwhich the machine isadaptedr't'orber propelled on'the ground.

The rotating basezl serves: to: mount" the nner-- :ating machinery,including the power plant, boom hoist drums, etc, all of whichmachinery- 11 is%housed*withine the cab l-0. In the 'particularmachine-- illustrated, the rotatingbase also sup- .ports-thecontrolitowen M which is ofi'set toward r one-side! of the planeofipivotal:mevementof the it boom.

The foot end: of the .boom t2 TiS pivoted at 113 tow therotating-:basa-to provide for upwardand downwardtmovement thereofthrough a range .such. ,asdefined -bythe "positions.- indicated; .inFigmaese 1: and 3.. Front compression gantry legs 1 I :4 extend..upwardly and L reanwardly from. points adjacent the pivot-:axis w-iortheboom, to sup- .portthegantry. headshafti l5... Rear tension.gan-

try legsw t6 extend. downwardly (from: the gantry .headshaf-tto beanchoredi to-the rotating. base.

Raising-and. loweringnot. theboom. is controlled by the boom hoistlcableI]. which is. adapted -,to bereevedoven sheaves I8 mounted onthel-gantny headshaft- 15.,(see Eigure.4).,fthe boomhoist cableultimately being carried. down into the cabifor cooperationswithaboomhoist drum. The cable l.1is,.,also. associated withsheaves 18" carriedby a. sling, l9: whlchlfisisunported. from the point of the boom'bymeans oflslingjcables 2U. Ordinarily aanumber .01111118 or cable I I areprovided between sheavestlfB and I8.

accordance with the invention, the gantry shaft [5 carries. pairs ofupwardly projecting plates 2l', which are apertured' toward their upper.ends to receive pivot trunnions 22 projecting in :axial alignment with"each other transversely ot sleeves 23, one such sleeve being 'monnteddnthis mannenadj acent each end 'of thegantryshaft 15. Each sleevecooperates with i an assembly of telescopic-boomstop members which areextended forwardly therefrom for attachment to the" boom,

was isrillustrated' in the drawings. Since. the two assembliesoftelescopic :boom stopmembers are of the: same construction, only"oneneedfibedascribed.

Thea assemblydsi best shown; inliigures' 5; and-6 and? includes: an:10111383111081". tubular member 24 having a rear end,capJwZSsseI'Ving-mas:a stopwhen cooperating stop parts.

the cap abuts the rear end of sleeve 23 upon extension of the assembly.Tubular member 24 extends through and beyond sleeve 23 and is providedwith an annular abutment 26 adapted to abut the forward end of sleeve 23upon collapsing of the assembly when the boom swings upwardly. A secondtubular member 21 extends into the forward end of member 24, the tube 21having an annular abutment 28 which, upon collapsing of the telescopicassembly, is adapted to abut the fitting 29, which latter is secured tothe forward end of the outermost tube 24. The tube 21 is restrained frombeing drawn completely out of tube 24 by an abutment sleeve 30 ofdiameter such as to engage the fitting 29. Sleeve 30, together withanother sleeve indicated-at 30a, serve to guide the telescopic movementof tube 21 in tube 24.

A third or innermost tube 8! extends into the forward end of tube 21,this third tube having a 'forked terminal fitting 32 pivotall connectedwith the apertured ear 33, which is welded or otherwise secured to thestructure of the boom (see Figure 4). The terminal fitting 32 alsoserves as an abutment to restrict movement of tube 3| into tube 21, thefitting being arranged to engage the end of the hollow cap 34 on theforward end of tube 21. A sleeve abutment 35 on tube 3| cooperates withthe hollow cap 34 in preventing movement of tube 3| completely out oftube 21. Another sleeve 35a cooperates with sleeve 35 to guide thetelescopic movement of tube 3| in tube 27.

Toward the rear end of the assembly (the left end as viewed in Figuresand 6), a cushion device such as a compression spring 36 is arrangedwithin the tube 24 to react between the inner end of tube 21 and the endof a spacer sleeve 3! disposed in the tube 24 just inside of the cap 25.

In the position of the parts illustrated in Figure 5, all of theelements of the assembly are collapsed or telescoped to the maximumpossible extent and, from examination of this figure, it will be seenthat the several abutments (26, 28 and 32) are all in engagement withthe respective In this condition, the spring 36 is compressed althoughthere still remains slight spacing between the turns of the spring, sothat the compression forces will be carried through the severalabutments referred to. The showing of Figure 5 corresponds to theposition of the boom illustrated in Figure 3.

In Figure 6, the assembly of telescoping tubes is illustrated extendedto the maximum possible degree, which corresponds to a boom positionsomewhat lower than that illustrated in Figure 1. In the preferredconstruction, the stop assemblies are arranged to have a degreeofextension suilicient to prevent, the parts from being placed undertension even when the boom is lowered to the maximum limit of the normaloperating range.

Thus it is contemplated that downward movement of the boom shallnormally be restrained only by the action of the boom hoist cable, but

-' and well braced reaction point for the boom stops when the latter actin compression to limit up- 1 Ward movement of the boom.

I claim:

1. In a load handling machine having a gantry and a boom, the latterbeing mounted for upward and downward swinging movement, mechanism forarresting upward swinging movement of the boom comprising a sleevepivotally mounted on the gantry, a tubular member slidable in saidsleeve, a compression member telescopically associated with the tubularmember and connected with the boom, first stop means on the tubularmember positioned to engage the sleeve, and second stop means on thecompression member positioned to engage the tubular member, both of saidstop means being operative in the upper range of swinging of the boom tolimit telescopic movement of the compression member into the tubularmember and sliding movement of the tubular member into the sleeve,whereby said members act in compression to limit the range of upwardswinging of the boom.

2. In a load handling machine having a gantry and a boom, the latterbeing mounted for upward and downward swing movement, mechanism forarresting upward swinging movement of the boom comprising threetelescopically associated members, one pivotally connected with theboom, one pivotally connected with the gantry and the third beingtelescopically intermediate and serving to interconnect the first two,stop means at the outer end of the internal member positioned to engagethe outer end of the intermediate member upon telescoping of theinternal member into the intermediate member when the boom movesupwardly, and stop means intermediate the ends of the intermediatemember positioned to engage the free end of the external member upontelescoping of the intermediate member into the external mem her whenthe boom moves upwardly, whereby said external member acts incompression in limiting the upward swinging of the boom.

3. In a load handling machine having a gantry and a boom, the latterbeing mounted for upward and downward swinging movement, mechanismpivotally connected at one end to the boom and at the other to thegantry for arresting upward swinging movement of the boom, saidmechanism comprising a plurality of telescopically associated members,stop means on one telescopic member positioned to engage the end of asecond member into which it telescopes when the boom swings upwardly,and a yielding device connected with one of said members and adapted toreact upon the other during the minor fraction of the upward movement ofthe boom which precedes engagement between said stop means and. saidend, whereby said second member acts in compression in. positivelylimiting the range of upward swinging of the boom.

WILLIAM M. HUSTON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 538,186 Widdows Apr. 23, 1895546,088 Clancy et al Sept. 10, 1895 1,021,545 Messick Mar. 26, 19121,369,165 Cochran et a1 Feb. 22, 1921 1,563,860 Jacobson Dec. 1, 19251,658,873 Younkman et a1. Feb. 14, 1928 1,855,217 Berg Apr. 26, 19322,151,057 Suth Mar. 21, 1939 2,198,793 Schroeder Apr. 30, 19 102,318,491 Johnson May 2, 1943

